Mourinho will have just cause for complaint, however, after referee Anthony Taylor waved away what looked a clear penalty when Cesc Fabregas went down under Matt Targett's challenge, only to receive a caution for diving.

Southampton even survived Morgan Schneiderlin's late sending off, after a second yellow card for a reckless challenge on Fabregas.

The roars that rang around St Mary's at the final whistle revealed a mixture of relief at Southampton claiming a point but also admiration for the manner in which their team had dug so deep as Chelsea pressed.

For Chelsea and Mourinho, there was disappointment at the failure to fashion a victory and the casting aside of two points that will open the door a little further for reigning champions Manchester City.

The base of Nemanja Matic and John Mikel Obi provided the platform for Fabregas to play in a more advanced role and he posed problems for Southampton early on.

But Southampton's game plan was clear - manager Ronald Koeman wanted his players to press Chelsea in possession then use the pace of Mane in behind the opposing central defenders when the opportunity arose.

And the ploy worked exactly as Koeman had planned when Saints took the lead after 17 minutes, Mane showing too much pace for John Terry as he collected Dusan Tadic's clever pass before beating keeper Thibaut Courtois with a composed finish.

It gave Southampton impetus and their energy was restricting Chelsea's options until a moment of individual brilliance from Hazard put Mourinho's side level in first-half stoppage time.

Fabregas could claim his 13th Premier League assist of the season with a fine pass but the hard work was done by Hazard, who cut inside before placing a perfect low right-foot shot beyond the reach of Forster.

Chelsea, who introduced Willian for Andre Schurrle at half-time, were infuriated when Fabregas had a penalty appeal rejected after he went down under challenge from Targett.

He looked to have been clipped by the Saints defender, who appeared to lose his footing slightly, but referee Taylor not only refused Chelsea's claims but added insult to injury by showing Fabregas a yellow card for diving.

Southampton's work-rate in the first half had been matched by their defensive discipline and resilience in the second as Chelsea pushed constantly but were unable to get anywhere near troubling Forster.

Even with reduced numbers after Schneiderlin's sending off, Southampton held out and once again showed they are side to be reckoned with this season.

Southampton manager Ronald Koeman:

"One point against Chelsea is worth three points against another opponent. I'm proud of the spirit and organisation.

"I'm disappointed we conceded before half-time, at some moments we were lucky but you need that against these opponents.

"We played with organisation until the last minute and the spirit we showed was unbelievable and we did not make stupid mistakes like we did against City and United.

"The second half was difficult, we fight until the last second and that was the key today.

"We can be very happy with our position in the table, we play good football and the fans love the way we play. We had a difficult two weeks but the spirit is back, the confidence is back.

"It's halfway and if we keep going like this we can fight for a good position."

It was a sunny but nippy day on the South Coast

It was the first meeting between Jose Mourinho and Ronald Koeman in the Premier League

Sadio Mane made John Terry pay for his hesitancy in the 17th minute

Chelsea's Eden Hazard - one of the best players at St Mary's - equalised on the stroke of half-time